ATOMIC SCALE CHARACTERIZATION OF OXYGEN VACANCY DYNAMICS BY IN SITU REDUCTION AND ANALYTICAL ATOMIC RESOLUTION STEM.
- BROOKHAVEN NATIONAL LABORATORY
In this study, we present nano-scale investigations of point defect dynamics in perovskite oxides by correlated atomic resolution high angle annular dark field imaging (HAADF) and electron energy loss spectroscopy (EELS). The point defect dynamics and interactions during in-situ reduction in the microscope column are analyzed. In particular, oxygen vacancy creation, diffusion and clustering are studied, as oxygen vacancies comprise the majority of the point defects present in these perovskite oxide systems [1]. The results have been acquired using the JEOL2010F, a STEM/TEM, equipped with a 200 keV field emission gun, a high angle annular dark field detector and a post column Gatan imaging filter (GIF). The combination of the Z-contrast and EELS techniques [2] allows us to obtain direct images (spatial resolution of 2 {angstrom}) of the atomic structure and to correlate this information with the atomically resolved EELS information (3s acquisition time, 1.2 eV energy resolution). In-situ heating of the material is performed in a Gatan double tilt holder with a temperature range of 300 K-773 K at an oxygen partial pressure of P{sub O{sub 2}} = 5 * 10{sup -8} Pa.
- Research Organization:
- Brookhaven National Lab., Upton, NY (US)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 807719
- Report Number(s):
- BNL--69649; KC0201010
- Country of Publication:
- United States
- Language:
- English
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